In hand held and portable electronic devices such as cellular phones, pagers, and two-way radios, the trend is toward smaller and more compact designs to minimize the size and weight of the device and to allow for increased density of the electronic circuitry mounted on the printed circuit boards within the devices. Therefore, it is important to maximize the density of such devices by utilizing "true surface mount" components, i.e. mounting components and connectors on both surfaces of the circuit boards, and by minimizing the distance between the printed circuit board and the connector mounted thereon. However, if components or connectors, and in particular the component or connector terminals, are placed too close to the surface of the printed circuit board, during processing of the board the reflow soldering may cause "solder-wicking" of the molten solder or spreading of the reflowed solder into exposed surfaces of the connector terminals.
The "creeping" or wicking of the solder within the terminal can interfere with the electrical connection between the connector terminals and mating component leads by increasing the insertion force of a mating pin or blocking insertion altogether, by causing solder bridging and/or short circuits within the terminal, or by causing loss of functionality of resilient beams of the terminal by reducing or eliminating contact normal forces altogether. Therefore, to minimize the risk of solder-wicking in these electronic devices, the designs typically call for spacing the connector or component away from the surface of the circuit board to create a gap which minimizes the exposed surfaces of a terminal along which the molten solder can flow. However, this approach is not necessarily consistent with the trend toward high density and compact miniaturized devices, since the gap between the circuit board and the connector takes up valuable space. Eliminating the gap by mounting the connectors and/or the components "flush" with or directly on the surface of the circuit board would allow the designs to achieve higher density.
The present invention is directed to solving the above problems by providing a surface mount terminal socket assembly which prevents solder-wicking and therefore allows the assembly to be mounted directly to the surface of the circuit board to minimize the overall profile of the assembly. The assembly can therefore be flush-mounted to the surface of a printed circuit board without the danger of problems caused by solder-wicking.